Question

我正在尝试选择要素，并使用ArcGIS javascript API将地图缩放到所选要素。

我已经进行了检查，以确保查询返回的是实际结果，因此应该检索到数据。我将脚本基于FeatureLayer入门-4.11。代码在下面。

<script>
  require([
    "esri/Map",
    "esri/views/MapView",
    "esri/layers/FeatureLayer"
  ], function(Map, MapView, FeatureLayer) {
    var map = new Map({
      basemap: "hybrid"
    });

    var view = new MapView({
      container: "viewDiv",
      map: map,

      extent: {
        // autocasts as new Extent()
        xmin: -9177811,
        ymin: 4247000,
        xmax: -9176791,
        ymax: 4247784,
        spatialReference: 102100
      }
    });

    /********************
     * Add feature layer
     ********************/

    // Carbon storage of trees in Warren Wilson College.
    var featureLayer = new FeatureLayer({
      url:
        "http://someURL/FeatureServer/45"
    });

    map.add(featureLayer);

    const query = new Query();
    query.where = "LASTNAME = 'GLOVER'";
    query.outSpatialReference = { wkid: 102100 };
    query.returnGeometry = true;
    query.outFields = [ "LASTNAME" ];

    featureLayer.queryFeatures(query).then(function(results){
      var newextent = esri.graphicsExtent(results.features);
      map.setExtent(newextent,true);

    });

  });
</script>

我本来希望地图缩放到选定多边形的程度，但事实并非如此。没有错误消息出现-地图仅显示原始范围。

希望有人可以指出我正确的方向。

Answer 1

用const query = new Query();替换行const query = featureLayer.createQuery();，因为您没有在Query中声明require，例如：

require([
  "esri/Map",
  "esri/views/MapView",
  "esri/layers/FeatureLayer",
  "esri/tasks/support/Query"
], function(Map, MapView, FeatureLayer, Query) {

从ArcGIS Javascript API版本4. *开始，您可以从featureLayer：https://developers.arcgis.com/javascript/latest/api-reference/esri-layers-FeatureLayer.html#createQuery创建查询，并使用MapView https://developers.arcgis.com/javascript/latest/api-reference/esri-views-MapView.html#goTo来控制视图：

featureLayer.queryFeatures(query).then(function(results){
  const features = results.features;
  view.goTo(features[0].geometry);
});

缩放到选定的功能

1 个答案: